Efficient Synthesis of 12-Aryl-8,9,10,12-tetrahydrobenzo[a]-xanthen-11-ones using Ionic Liquid Pyrazinium Di(hydrogen sulfate) {Py(HSO4)2} as a Novel, Green and Homogeneous Catalyst

An efficient and simple solvent-free procedure for the syn- thesis of 12-aryl-8,9,10,12-tetrahydrobenzo(a)-xanthen-11-one de- rivatives via the one-pot multi-component condensation of dimedone with aromatic aldehydes and β-naphthol in the presence of protic acidic ionic liquid pyrazinium di(hydrogen sulfate) {Py(HSO4)2} as a green and homogeneous catalyst is described. All reactions proceed efficiently, and the title compounds are produced in high yields and in short reaction times.